inference: rename internal `amd` provider to generic `openai_responses`

Drop GitHub references from landing page and README; clone via HF Space repo

BLOG: clean up dangling 'all four / table' references after Opus rows removed

landing page: drop footer, drop Opus mentions, lead with 2x Sonnet headline

Update BLOG.md

README/BLOG: feature canonical 110-step GRPO numbers as the headline

Hackathon cleanup: drop assets/ and scripts/ (notebook embeds curves + eval); patch README/BLOG to remove dead refs

server/app.py: add HTML landing page at /

Hackathon: GRPO single-GPU notebook with embedded curves + eval table (50 steps, GRPO step-040 beats SFT-init +10.6%)

HF Space: 4-dept SimMart env + 1.5B SFT+GRPO training (hackathon submission)